Devices such as a display device for a driver and an RSE (Rear Seat Entertainment) display device for a rear seat passenger are known as in-vehicle devices mounted on a vehicle such as a car. Further, in recent years, an in-vehicle information terminal which communicates with communication terminals in a vehicle using wired connection such as cables or wireless connection such as Bluetooth (registered trademark) is proposed as one of in-vehicle devices (e.g., Patent Documents 1 and 2).